Carburetors are reliable, robust mechanisms for efficiently metering fuel to an internal combustion engine. A carburetor meters the appropriate amount of fuel according to engine demand based on intake airflow to the engine. Generally, carburetors operate on the principle that as the velocity of airflow through a restriction increases, its pressure decreases. Carburetors are configured to take advantage of the pressure differential created between atmospheric pressure surrounding the carburetor and a low pressure region created inside the carburetor, usually by way of a venturi. As an engine draws air through the venture, the low pressure region created by the increasing air velocity meters a proportional amount of fuel into the intake airflow stream. As passive devices, carburetors are both reliable and robust, while thoroughly mixing fuel with incoming airflow which enhances efficient combustion.
While carburetors are simple and cost effective fuel delivery systems, modern emission requirements have limited the application of carburetors on newer products. Many applications have implemented electronic fuel injection in order to maintain precise control of fuel delivery, which allows catalytic converters to be used in an emissions reduction strategy. The introduction of electronic fuel injection has added complexity, cost, weight, and increased electronic load to modern engines. Fuel injection systems rely on a sensor network. The failure of any single sensor can drastically reduce the emissions performance of the fuel system.
In order to continue to benefit from the carburetor's advantages, improvements to traditional carburetor design are needed in order to ensure the carburetor's ability to meet emission requirements for modern engines.